DHCP not handing out addresses

Hi all

I have Windows Server 2008 sp2 roles AD DNS and DHCP.

Several days my server DHCP is "hangs"a few hours after restart

C:\Windows\system32\svchost.exe -k DHCPServer run on 50 % on procesor and mmc not responding I must before kill proses svchost and start DHCP islooks good but not response to client PC